feat(ui): add steampunk village visualization for agent orchestration

Interactive SVG village where AI delegates appear as geese walking between
role-specific buildings (library for researchers, forge for generics, factory
for workers, etc.) via A* pathfinding with tiered terrain costs.

Includes:
- Real-time SSE dashboard with delegate registry, wall feed, and workshop
- ASCII map system with visual editor (editor.html)
- Standalone fullscreen village page (village.html)
- Map validator script with pathfinding analysis (scripts/validate-map)
- Pub/sub state management, lit-html rendering, zero build step
- 3 CDN deps: lit-html, marked, DOMPurify (version-pinned)

Security: CSP headers, DOMPurify + lit-html auto-escaping, parameterized
SQL, read-only DB, input validation, subprocess_exec (not shell).

Accessibility: WCAG AA contrast, ARIA roles/states, keyboard navigation,
focus trapping, prefers-reduced-motion support.

Crossfire-reviewed to 9/10 by independent models.

Author: tlongwell-block

.gitignore

@@ -13,6 +13,9 @@ UTILITIES/
 .beads/
 .beads-ui/
 
+# Goose
+.goose/
+
 # Knowledge system (local per user, not shared)
 /CATALOG.md
 /TAGS.md

AGENTS.md

@@ -29,6 +29,8 @@ Filenames: `ALL_CAPS_WITH_UNDERSCORES.md` (e.g., `OAUTH_PKCE_IMPLEMENTATION_NOTE
 
 The **Town Wall** (`gtwall`) is a broadcast communication tool for real-time coordination between delegates. Per-session walls, position-tracked per reader.
 
+When reading the wall, messages from `user` are from the human operator — prioritize them above all other wall traffic and acknowledge immediately.
+
 **Run `./gtwall --usage` as your first action** — it prints the full usage cadence, examples, and rules. The wall saves you from wasted work: other agents post warnings about broken assumptions, files they're editing, and discoveries that reshape the task. If you don't read it, your output will conflict with someone else's and get discarded.
 
 ### Wrap-Up Protocol

scripts/goosetown-ui

@@ -9,10 +9,35 @@ from pathlib import Path
 
 import uvicorn
 from starlette.applications import Starlette
+from starlette.middleware import Middleware
+from starlette.middleware.base import BaseHTTPMiddleware
 from starlette.responses import JSONResponse, RedirectResponse, StreamingResponse
 from starlette.routing import Mount, Route
 from starlette.staticfiles import StaticFiles
 
+
+# Security model: This server is designed for localhost-only use (binds to 127.0.0.1).
+# It has no authentication, no CORS restrictions, and serves all session data to any
+# connecting client. Do not expose to a network without adding auth and access controls.
+
+
+class SecurityHeadersMiddleware(BaseHTTPMiddleware):
+    async def dispatch(self, request, call_next):
+        response = await call_next(request)
+        response.headers["Content-Security-Policy"] = (
+            "default-src 'self'; "
+            "script-src 'self' https://cdn.jsdelivr.net; "
+            "style-src 'self' 'unsafe-inline' https://fonts.googleapis.com; "
+            "font-src https://fonts.gstatic.com; "
+            "connect-src 'self'; "
+            "img-src 'self' data:; "
+            "object-src 'none'; "
+            "base-uri 'none'; "
+            "frame-ancestors 'none'; "
+        )
+        response.headers["X-Content-Type-Options"] = "nosniff"
+        return response
+
 SCRIPT_DIR = os.path.dirname(os.path.abspath(__file__))
 PROJECT_DIR = os.path.dirname(SCRIPT_DIR)
 
@@ -22,6 +47,8 @@ WALLS_DIR = os.path.expanduser("~/.goosetown/walls")
 CHILD_PATTERN = re.compile(r"Task (\d{8}_\d+) started in background")
 GTWALL_ID_PATTERN = re.compile(r"Your gtwall ID is (\S+)")
 DELEGATE_NAME_PATTERN = re.compile(r"You are (\S+)\.")
+# IMPORTANT: These patterns are duplicated in ui/js/buildings.js (inferRole function).
+# If you change patterns here, update the JS version to match.
 ROLE_PATTERNS = {
     "orchestrator": re.compile(r"orchestrat", re.I),
     "researcher": re.compile(r"research", re.I),
@@ -395,6 +422,8 @@ async def sessions_tree_watcher():
 
 # ── SSE Endpoint ────────────────────────────────────────────────────────────
 async def sse_endpoint(request):
+    if len(clients) > 50:
+        return JSONResponse({"error": "too many connections"}, status_code=503)
     queue: asyncio.Queue = asyncio.Queue(maxsize=1000)
     clients.append(queue)
     last_event_id = request.headers.get("Last-Event-ID")
@@ -438,10 +467,12 @@ async def sse_endpoint(request):
 # ── REST ────────────────────────────────────────────────────────────────────
 async def messages_endpoint(request):
     sid = request.path_params["session_id"]
+    if not re.match(r'^[a-zA-Z0-9_-]{1,128}$', sid):
+        return JSONResponse({"error": "invalid session id"}, status_code=400)
     before = request.query_params.get("before")
 
     try:
-        limit = min(int(request.query_params.get("limit", "100")), 500)
+        limit = max(1, min(int(request.query_params.get("limit", "100")), 500))
         with db() as cur:
             if before:
                 cur.execute(
@@ -458,14 +489,49 @@ async def messages_endpoint(request):
                 )
             rows = [{"id": r[0], "role": r[1], "content_json": r[2], "created_timestamp": r[3]} for r in cur.fetchall()]
     except Exception as e:
-        return JSONResponse({"error": str(e)}, status_code=500)
+        print(f"⚠️  messages_endpoint error: {e}", file=sys.stderr)
+        return JSONResponse({"error": "internal error"}, status_code=500)
 
     rows.reverse()
     return JSONResponse({"session_id": sid, "messages": rows, "has_more": len(rows) == limit})
 
 
+async def wall_post_endpoint(request):
+    """Post a message to gtwall. Shells out to ./gtwall — no duplicated logic."""
+    try:
+        body = await request.json()
+        message = body.get("message", "").strip()
+        if not message:
+            return JSONResponse({"error": "empty message"}, status_code=400)
+        if len(message) > 4096:
+            return JSONResponse({"error": "message too long (max 4096 chars)"}, status_code=400)
+
+        wall_file = config.get("wall_file", "")
+        if not wall_file:
+            return JSONResponse({"error": "no wall file configured"}, status_code=503)
+
+        gtwall_path = os.path.join(PROJECT_DIR, "gtwall")
+        env = {**os.environ, "GOOSE_GTWALL_FILE": wall_file}
+        proc = await asyncio.create_subprocess_exec(
+            gtwall_path, "user", message,
+            env=env,
+            stdout=asyncio.subprocess.PIPE,
+            stderr=asyncio.subprocess.PIPE,
+        )
+        await proc.wait()
+        if proc.returncode != 0:
+            stderr_output = (await proc.stderr.read()).decode().strip()
+            print(f"⚠️  gtwall failed (rc={proc.returncode}): {stderr_output}", file=sys.stderr)
+            return JSONResponse({"error": "failed to post message"}, status_code=500)
+        return JSONResponse({"ok": True})
+    except Exception as e:
+        print(f"⚠️  wall_post error: {e}", file=sys.stderr)
+        return JSONResponse({"error": "internal error"}, status_code=500)
+
+
 async def config_endpoint(request):
-    return JSONResponse(config)
+    safe_keys = ("wall_id", "port", "parent_session_id")
+    return JSONResponse({k: config[k] for k in safe_keys if k in config})
 
 
 async def root_redirect(request):
@@ -480,10 +546,11 @@ def create_app() -> Starlette:
             Route("/", root_redirect),
             Route("/events", sse_endpoint),
             Route("/api/messages/{session_id}", messages_endpoint),
+            Route("/api/wall", wall_post_endpoint, methods=["POST"]),
             Route("/api/config", config_endpoint),
             Mount("/ui", StaticFiles(directory=ui_dir), name="ui"),
         ],
-
+        middleware=[Middleware(SecurityHeadersMiddleware)],
         on_startup=[start_background_tasks],
     )